if your 3rd-party css does not use unique id's or classes, then you
could create your own (which will enable you to use !important):
1. locate the html for the candy, in your site's html pages.
2. surround it with a div with an id that does not appear anyplace in
the rest of your site:
<div id="candy">...</div>
3. open each of the candy's css files, and precede every element with
#candy:
#candy ul li { width: 100% !important; }
DONE!
If the candy appears throughout the site, then you can use a class-
name instead of an id name.